The dunks, or larvicide, will kill mosquito larvae, and are part of the town's mosquito defense plan.

Meagan Bonnot, a mother of two, said she is concerned about playing in her backyard with her children while West Nile virus continues to threaten North Texas.

"It's just scary, thinking that that could be your child, so as a parent, you want to do everything you can do to protect them from that," she said.

Bonnot went to Town Hall on Monday to pick up free mosquito dunks. She is trying them out in her backyard pool.

"I think that's awesome just to have that available to everyone," she said. "I didn't even know it existed."

Chuck Dumas, town environmental services director, said there have been seven confirmed human cases of West Nile virus in Flower Mound. He said he hopes the dunks will help residents boost the town's mosquito control.

"The dunks contain a natural-occurring bacteria, and they produce a toxin, and the toxin specifically attacks mosquito larvae in standing water, so if you have stagnant pools, planter basins, pet baths, bird baths, they can be used there," he said.

The mosquito dunks are not the town's only line of defense. It is also spraying for mosquitoes in areas where West Nile virus is a threat

"We want to do everything we can, so education, surveillance, trapping, larvicide -- all of that together -- makes in an approach," Dumas said.

The mosquito dunks are available to Flower Mound residents at Town Hall. The program lasts until supplies run out.